The Renewable Energy Sources: Explanation and Examples

Renewable Energy Sources

Renewable energies are those energy sources whose use respects natural resources and, in general, human and planetary health. These are resources considered inexhaustible. Thanks to the self-regeneration capacity, in fact, the energy source remains practically infinite.

Some renewable energy sources, however, may become depleted in the future. This is the case of wood, for example, whose survival is threatened by continuous deforestation all over the world. Let’s see what are the existing renewable energy sources that are already widely used for electricity production.

Solar Power Energy

This type of energy is used for photovoltaic and solar systems. The former exploit solar irradiation. The latter, instead, allow the production of electricity thanks to the use of solar panels equipped with a water storage tank.

Many are the advantages of photovoltaic systems, which economically guarantee savings on electricity bills. Concessions are provided for the purchase of these facilities and zero-risk investments are available.

Solar systems have an assured lifespan of at least 30 years and do not require maintenance, apart from the change every ten years of the inverter, the only electrical component. Finally being installed in the unused spaces of the houses, and using a home solar battery for the energy saving, they are not bulky and they are very useful.

Solar panels are usually made of silicon. It is a material that, by receiving the light of the sun’s rays, produces electricity. Solar energy is widely used at home for heating water, for the house or feeding refrigerators and air conditioners. It is often also used for the distillation of seawater and the production of freshwater.

Wind Energy

Thanks to the power of the wind it is possible to generate mechanical energy and, at a later time, also electricity. The mechanical energy obtained from the wind is that obtained, for example, in windmills used for grinding wheat and other agricultural products. The mill works thanks to the thrust of the wind which, by moving the blades of the mill, operates the mechanism’s activation gears.

The electricity is obtained thanks to the action of wind on wind turbines installed on top of a pole and connected to a mechanical rotor equipped with a dynamo. The latter allows the transformation of mechanical energy into electrical energy.

Wind power plants are ideal in the plains, where the wind is constant. Thanks to technology, however, it is now possible to install wind turbine blades even in the middle of the sea.

For the production of wind energy by private individuals and companies, the mini-wind solution is available, which is easy to install and small in size. A mini wind system consists of a steel support pole, 5 to 30 meters high, a turbine and electronic control equipment.

These plants are advantageous both for saving on the electricity bill and for the impact on the environment. Furthermore, maintenance works are practically non-existent.

Biomass Energy

Biomasses are biological products used as fuels or fuels for the purpose of creating electricity. Through biomasses, which are waste from agricultural and industrial products (such as urban waste, product waste from farms, firewood), electricity is produced at low cost and with minimal environmental impact.

The quantities of carbon, nitrogen and sulfur released in the air from the combustion of these materials are considerably lower than those emitted by fossil fuels.

The use of biomasses includes the chemical transformation of the organic material into biogas, ie methane ready for use; the burning of wood or vegetable oils for the creation of electricity or the production of heat; the production of products for agriculture such as the compost used for fertilizing the fields.

Geothermal Energy

This is the energy that can be obtained from the earth’s subsoil, thanks to the heat coming from its depth.

The system involves the installation in the subsoil of an evaporator of a refrigerant circuit and an underground coil for several meters, the system allows the refrigerant to transform into gas.

There are two types of geothermal energy. The classic one, which exploits geological and volcanological anomalies, and the low temperature one, which exploits the subsoil for the production of electricity. The geothermal system can be equipped with various types of probes.

There are the vertical ones inserted in the ground at several tens of meters, the horizontal ones used both for trench installations and distributed over large surfaces. There are spiral probes, which provide a construction in a horizontal direction at about four or six meters deep and that require ample space, and energy poles, ie vertical probes inserted in the foundation piles.

This energy is used to supply heating systems and air conditioners. Geothermal energy can also be used to heat a home by installing floor systems that include a series of coils placed under the radiant floor.

Many advantages derived from the use of geothermal energy. This energy, in addition to polluting the environment little, is always available throughout the day. Furthermore, the plants have a guaranteed life guarantee for at least 50 years. This is for sure a very beneficial long-term investment.

Hydraulic Energy

It is the energy generated by the force of water, with waves and tides. To understand how energy can be created from water, just think of the energy emanating from the sun. The sun warms the water.

This evaporates and then falls back to the earth’s surface in the form of rain or snow. This generates a movement of the masses of water which, falling from a gradient, generates kinetic energy.

The kinetic energy is in turn transformed into mechanical energy through the use of turbines, and electricity is reached by combining an electric generator.

This method is used in hydroelectric power plants located mainly in the mountains, to exploit the force of earth’s gravity in a natural way. Energy can also be obtained from rivers, natural and artificial waterfalls.

The strength of hydroelectric plants depends on the positioning of the plant, the difference between the height where the water resource is located and the level to which it returns after passing through the turbine, and the mass of water flowing through the plant.

The most exploited hydroelectric plants are the basin ones, which exploit natural or artificial lake basins. The storage or tank systems instead obtain the availability of water in the tank with an electromechanics lift given by pumps or by the same production turbine.

Furthermore, there are new types of plants that provide water supplies from canals and pipelines exploiting the energy produced also for reclamation canal systems, condenser cooling circuits and other water systems.

Why use Renewable Energy

Renewable sources are recommended for many reasons. The first is economic savings, guaranteed by the purchase of a plant-powered by natural sources. They are also recommended because they produce less pollution, thanks to the emission of clean energy and the use of technologies that use renewable resources to produce electricity.

Energy, however, is still largely produced by the use of fossil fuels which, being exhaustible, may one day no longer be available. Just think of oil, which besides being very expensive, pollutes much more than a natural and renewable source of energy such as the sun, wind, water and earth.

Thanks to TED-Ed
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